Method and device for data transmission between a central unit and a data terminal

Abstract

The invention relates to a process for data exchange via a communications channel between a central unit, which processes, stores and provides data, and a data terminal device. Initially, a permanently unchanged application-independent query structure (general query structure) is stored both in the central unit and in the data terminal device, as are a small number of permanently unchanged application-independent response formats. For each application, the specific query structure is defined on the basis of the general query structure and is stored in the central unit in the form of a parameter set. As needed, the data terminal device requests from the center unit, via the communications channel, a specific query structure not yet stored in the data terminal device and receives and stores the applicable parameter set. To implement a query functionality, the applicable specific query structure is created in the data terminal device from the general query structure on the basis of the applicable parameter set and, after being at least partially filled out with values by the user, is transmitted to the central unit. The data terminal device makes responses transmitted from the central unit in response to queries available to the user based on one of the stored response formats, which is designated in the particular response.